: a device that is actuated by power from one system and supplies power usually in another form to a second system
Device that converts one form of energy to another. A microphone is an acoustic transducer, converting sound waves into electrical signals. Different types of transducers act on heat, radiation, sound, strain, vibrations, pressure, and acceleration; they may output mechanical, electrical, pneumatic, or hydraulic signals. Examples include strain gauges, loudspeakers, photocells, transformers, and thermocouples.